body, div, dl, dt, dd, ul, ol, li, h1, h2, h3, h4, h5, h6, pre, code, form, fieldset, legend, input, button, textarea, p, blockquote, th, td {
    margin: 0;
    padding: 0;
}

body {
    background: #232F55;
    background-size: cover;
    color: #555;
    font-size: 14px;
    font-family: Verdana, Arial, Helvetica, sans-serif;
}

td, th, caption {
    font-size: 14px;
}

h1, h2, h3, h4, h5, h6 {
    font-weight: normal;
    font-size: 100%;
}

address, caption, cite, code, dfn, em, strong, th, var {
    font-style: normal;
    font-weight: normal;
}

a {
    color: #fff;
    text-decoration: none;
    -webkit-tap-highlight-color: rgba(0, 0, 0, 0);
}

a:hover {
    text-decoration: none;
}

img {
    border: none;
}

ol, ul, li {
    list-style: none;
}

input, textarea, select, button {
    font: 14px Verdana, Helvetica, Arial, sans-serif;
    outline: none;
}

table {
    border-collapse: collapse;
}

html {
    overflow-y: scroll;
}

div, header, footer, input, form, ol, ul, li {
    box-sizing: border-box;
}

.clearfix:after {
    content: ".";
    display: block;
    height: 0;
    clear: both;
    visibility: hidden;
}

.clearfix {
    *zoom: 1;
}

header {
    width: 100%;
    height: 40px;
    background: #1f232d;
    color: #fff;
    position: fixed;
    top: 0;
    z-index: 999;
    font-size: 18px;
}

.header_min {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
}

.header_min_back_off {
    width: 26px;
    position: absolute;
    left: 10px;
    top: calc((100% - 26px) / 2);
}